Dye-sensitized Photooxidation Research Articles

Activity of Xanthene Dyes Against Black Cutworm Larvae12

The activity of 3 xanthene dyes (rose bengal, erythrosin B, and phloxin B) against 3rd-6th instars of Agrotis ipsilon (Hufnagel) was investigated in the laboratory. Toxic dyesensitized photooxidation reactions occurred after larvae ingested dye impregnated diet and were exposed to one of 3 levels (9200, 4400, or 1500 lux) of flourescent light intensity. At a concentration of 5 × 10−3 M, ingestion of rose bengal resulted in the highest level of mortality, followed by phloxin B and erythrosin B. The 3 dyes were most effective at the 2 highest light intensities. Mortality in 5th–6th instars as a function of dietary concentration of rose bengal and illumination time showed that LT50 values decreased with increasing dietary concentration. Relative toxicity of rose bengal was described by means of a pseudo 2nd-order rate constant of photooxidation (k2).

The effect of photochemical treatment of water on algal growth

A new method for the destruction of algae in surface waters by dye-sensitized photooxidation is described. The algae ( Peridinium, Pediastrum and Cosmarium) used as test organisms were inoculated in an artificial culture medium, containing a dye-sensitizer, with subsequent incubation in a controlled environment (20 ± 2°C, 14 h light, 10 h darkness). Water samples from Peridinium bloom in Lake Kinneret underwent similar treatment. The algicidal effect of various sensitizer concentrations and of different sunlight exposure times was investigated. Complete destruction of algae was obtained in about 2 weeks of incubation after exposure to solar radiation for 30–60 min in the presence of 0.25, 0.15 and 0.75 mg 1 −1 methylene blue or 0.5, 0.8 and 0.8 mg 1 −1 rose bengal in Peridinium, Pediastrum and Cosmarium cultures, respectively.

Detection of singlet oxygen production by ESR

SINGLET molecular oxygen is a very powerful oxidant. Its action is important in a variety of chemical and biological processes(1-4), for examples dye-sensitised photooxidation of lipids, proteins and nucleic acids(4), photodynamic inactivation of viruses(5) and cells(4), phototherapy of cancer(6,7), carcinogenesis(8), haemolysis of erythocytes(9), sensitisation of the human skin(4) and degradation of food(4). The methods used to detect singlet oxygen are unspecific, of low sensitivity or laborious. Photooxidation of 1,3-diphenylisobenzofuran seems to be the most widely used diagnostic test for (1)O(2). However, in the absence of additional control experiments this test does not prove the intermediacy of (1)O(2) (ref. 4) and 1,3-diphenylisobenzofuran has very low solubility and dimerises in aqueous solutions. Lion et al.(10) have proposed a new method to detect (1)O(2) involving the generation of stable nitroxide radicals when (1)O(2) reacts with the sterically hindered amine 2,2,6,6,-tetramethylpiperidin. When using this method to detect (1)O(2) in neutral aqueous solutions, we found no radical production. We report here our investigation of this problem, as it is biologically important to be able to detect (1)O(2) production in such solutions.

Biological activity of the endoperoxides derived from vitamin D derivatives by dye-sensitized photo-oxidation.

Biological activity of the endoperoxides derived from vitamin D derivatives by dye-sensitized photo-oxidation.

Dye-sensitized photo-oxidation of acid ribonuclease from pea cotyledons

In crude extracts, pea cotyledon acid ribonuclease is not inactivated by photo-oxidation, but after 150-fold purification, it is markedly inactivated when illuminated in the presence of methylene blue at pH 7.2. It is, however, still resistant to methylene blue-sensitized photo-oxidation at pH 5.4. These data suggest that photo-oxidation of methionine, cysteine and tryptophan has no effect on enzyme activity, whereas photo-oxidation of histidine markedly reduces catalytic acitivity. It is thus likely that the mode of action of acid ribonuclease from pea cotyledons is similar to that of pancreatic ribonuclease.

Photochemical properties of Ytbase in aqueous solution

Photoreactivity of Yt base [I] has been studied in aqueous solution [pH approximately 6] saturated with oxygen. Two photoproducts (II,III], resulting from irradiation at lambda = 253.7 nm and lambda greater than or equal to 290 nm, were isolated and their structures determined. The quantum yield for Yt base disappearance [zeta dis] is 0.002 [lambda = 313 nm]. It was shown that dye-sensitized photooxidation of Yt base in aqueous solution occurs according to a Type I mechanism, as well as with participation of singlet state oxygen. Quantum yields, fluorescence decay times and phosphorescence of Yt base have been also determined.

Oxydation photochimique d'amines tertiaires et d'alcaloïdes—X : Introduction d'un groupement fonctionnel en α de l'azote n b de la yohimbine par oxydation photosensibilisee

Dye-sensitized photooxidation of the imino-ether 5, prepared from yohimbine 1a, led to the α-amino nitrile 9a when the reaction was performed in the presence of oxygen and KCN. Derivative 9a was hydrolyzed to the amide 9b, the transformation of which to carboxamido-5β-yohimbine 15 was studied.

Light Intensity as a Critical Parameter in the Dye-Sensitized Photooxidation of the House Fly, Musca domestica1

Light intensity is a critical variable of the dye-sensitized photooxidation reaction, and the rate of house fly, Musca domestica , mortality is observed to increase with increasing light intensity. Relative toxicities were described for 6 xanthene dyes (rose bengal, octabromofluorescein, erythrosin B, phloxin B, eosin Y, and tetrachlorofluorescein) as a function of the 3rd-order rate constant of photooxidation, k3, obtained for each dye and determined from the LT50, tissue dye levels, and light intensity measurements. The ranking of these 6 xanthenes by their respective k3 values is almost identical to the ranking of these same dyes by their k2, or second-order rate constant. The number of accumulated photons needed to produce 50% mortality was observed to decrease with an increase in light intensity.

Ethylene formation by polymorphonuclear leukocytes. Role of myeloperoxidase.

Ethylene formation from the thioethers, beta-methylthiopropionaldehyde (methional) and 2-keto-4-thiomethylbutyric acid by phagocytosing polymorphonuclear leukocytes (PMNs) was found to be largely dependent on myeloperoxidase (MPO). Conversion was less than 10% of normal when MPO-deficient PMNs were employed; formation by normal PMNs was inhibited by the peroxidase inhibitors, azide, and cyanide, and a model system consisting of MPO, H2O2, chloride (or bromide) and EDTA was found which shared many of the properties of the predominant PMN system. MPO-independent mechanisms of ethylene formation were also identified. Ethylene formation from methional by phagocytosing eosinophils and by H2O2 in the presence or absence of catalase was stimulated by azide. The presence of MPO-independent, azide-stimulable systems in the PMN preparations was suggested by the azide stimulation of ethylene formation from methional when MPO-deficient leukocytes were employed. Ethylene formation by dye-sensitized photooxidation was also demonstrated and evidence obtained for the involvement of singlet oxygen (1O2). These findings are discussed in relation to the participation of H2O2, hydroxyl radicals, the superoxide anion and 1O2 in the formation of ethylene by PMNs and by the MPO model system.

Amino acid sequence of tyrosinase from Neurospora crassa.

The amino-acid sequence of tyrosinase from Neurospora crassa (monophenol,dihydroxyphenylalanine:oxygen oxidoreductase, EC 1.14.18.1) is reported. This copper-containing oxidase consists of a single polypeptide chain of 407 amino acids. The primary structure was determined by automated and manual sequence analysis on fragments produced by cleavage with cyanogen bromide and on peptides obtained by digestion with trypsin, pepsin, thermolysin, or chymotrypsin. The amino terminus of the protein is acetylated and the single cysteinyl residue 96 is covalently linked via a thioether bridge to histidyl residue 94. The formation and the possible role of this unusual structure in Neurospora tyrosinase is discussed. Dye-sensitized photooxidation of apotyrosinase and active-site-directed inactivation of the native enzyme indicate the possible involvement of histidyl residues 188, 192, 289, and 305 or 306 as ligands to the active-site copper as well as in the catalytic mechanism of this monooxygenase.

Dye-Sensitized Photooxidation in the House Fly, Musca domestica1

A series of 6 xanthene dyes—rose bengal, phloxin B, erythrosin B, eosin yellowish, fluorescein, and rhodamine B—caused a light-dependent toxicity in the house fly, Musca domestica , after oral ingestion. Relative toxicities were described by means of rate constants of photooxidation calculated for each dye which include both the LT50 and the tissue dye level. These values were compared with similar values determined for reactions in the boll weevil, Anthonomus grandis , and with the phosphorescence quantum yields of the dyes, the number of halogen substituents, and the halogen content by weight. Lowered mortality at higher dietary concentrations was due to lowered consumption and was taken as preliminary evidence of feeding inhibition.

Synthetic Photochemistry. XII. The Sensitized Photooxidation Reaction of Some Spirocyclic Derivatives of Vinylcyclopropanes

Abstract The dye-sensitized photooxidation of the Diels-Alder adducts prepared from 2-substituted tropones and spiro[2.4]hepta-4,6-diene was caried out. A marked difference in the reactivities was observed between the two structural types of adducts; 3,3-ethylene derivatives gave nor-epoxides, but 5,5-ethylene derivatives resulted in the recovery of the starting materials.

ChemInform Abstract: THE PHOTO‐OXIDATION OF HEXAMETHYLBENZENE BY SINGLET OXYGEN

AbstractDer Mechanismus der Titelreaktion von (I) unter Bildung des endo‐Peroxyhydroperoxids (IIa) wird beschrieben.

Destruction of coliforms in water and sewage water by dye-sensitized photooxidation

A new approach to disinfection of water and sewage water, by oxidative destruction of microorganisms by photosensitization, is described. Samples of water and sewage water, to which an inoculum of fecal Escherichia coli had been added, were exposed to solar radiation in the presence of a dye sensitizer, under continuous aeration. The effects of the sensitizer methylene blue at concentrations of 0 to 10 mg/liter, different radiation times from 0 to 2 h, and sunlight intensities of 0, 68, and 2,030 muE/m2 per s were investigated. In laboratory-scale experiments, 1.3 X 10(9) coliforms in 100 ml of oxidation pond municipal sewage water containing 0.5 mg of methylene blue were destroyed in about 30 min. Similar results were obtained with nonchlorinated potable water. These results demonstrate the possibilities available for the disinfection of water and sewage water by this method.

Dye-sensitized photoinactivation of the lactic dehydrogenase and acetylcholinesterase from the boll weevil, Anthonomous grandis

The lactic dehydrogenase and acetylcholinesterase enzymes of the boll weevil, Anthonomous grandis, have been shown to be inactivated by dye-sensitized photooxidation mediated by substituted xanthenes. The efficiency of the photooxidation reaction was correlated with the degree of halogenation of the dye molecule, the efficiency of the dye in singlet oxygen formation, and the strength of binding to lactic dehydrogenase. Changes in the in vivo levels of these enzymes due to ingestion of rose bengal by adult weevils are not further modified in the presence of light.

Photosensitised oxidation of 1-naphthols

Whereas oxidation of 1-naphthols with Fremy's salt often affords significant amounts of the corresponding 1,2-naphthoquinone dye-sensitised photo-oxidation gives exclusively the 1,4-naphthoquinone via the addition of singlet oxygen to the naphthalene ring.

Xanthene Dye-sensitized Photooxidation in the Black Imported Fire Ant, Solenopsis richteri1

Lethal dye-sensitized photooxidation reactions in the black imported fire ant, Solenopsis richteri (Forel), have been defined as a function of whole body concentrations of a series of xanthene dyes. Log probit analysis of mortality data has allowed calculation of LD50 values of 1.1×10−3M for dietary levels and 2.3×10−7 moles/ gm wet weight for whole body concentrations of rose bengal in ants illuminated with 3800 μW/cm2 light for 4 h. Comparative LT50 values were calculated for the xanthene dye series and related to whole body dye concentrations.

ChemInform Abstract: DYE‐SENSITIZED PHOTOOXIDATION OF PHENOTHIAZINE, AN ESR STUDY

Chemischer InformationsdienstVolume 6, Issue 43 Preparative Organic Chemistry ChemInform Abstract: DYE-SENSITIZED PHOTOOXIDATION OF PHENOTHIAZINE, AN ESR STUDY I. ROSENTHAL, I. ROSENTHALSearch for more papers by this authorR. POUPKO, R. POUPKOSearch for more papers by this author I. ROSENTHAL, I. ROSENTHALSearch for more papers by this authorR. POUPKO, R. POUPKOSearch for more papers by this author First published: October 28, 1975 https://doi.org/10.1002/chin.197543135Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume6, Issue43October 28, 1975 RelatedInformation

Dye-sensitized Photooxidation Reactions in the Boll Weevil, Anthonomous grandis1

Adult boll weevils, Anthonomous grandis , fed for 4 days from emergence on a dyeimpregnated artificial diet before illumination at 3800 μW/cm2 fluorescent light for 4 h yielded a dietary LD50 value of 9.9×10−4 moles/liter and a tissue LD50 value of 2.4×−7 moles/g wet weight for rose bengal. The dye-sensitized photooxidation reaction was treated mathematically and 2nd order rate constants of 4.50 liters/mole·min for dietary rose bengal and 2.25×104 g/mole·min for tissue rose bengal were calculated.

ChemInform Abstract: THE PHOTO‐OXIDE OF 1,3‐DIPHENYLISOBENZOFURAN

AbstractDas Diphenylisobenzofuran (I) reagiert mit Sauerstoff bei Belichtung in Gegenwart von Methylenblau bei ‐50°C zum Cycloaddukt (II), das Methanol unter Bildung des Hydroperoxides (III) addiert.